Effects of twin-block appliance on the anatomy of pharyngeal airway passage (PAP) in class II malocclusion subjects

Progress in Orthodontics

Table 3 The changes in the pharyngeal airway passage (PAP) dimensions among treatment and control group subjects

Variables	Groups						Comparison of mean difference among treatment and control groups (P-value)
	Treatment Group			Control Group
	Pre-treatment (T₀)	6-months Post-treatment (T₁)	Significance (P-value)	Pre-follow-up (T₀)	6-months Post-follow-up (T₁)	Significance (P-value)
	Mean ± SD	Mean ± SD	Significance (P-value)	Mean ± SD	Mean ± SD	Significance (P-value)
DNP (mm) (Ptm-UPW)	12.84 ± 5.77	13.76 ± 5.17	0.254^NS	12.01 ± 5.78	13.04 ± 5.15	0.065^NS	0.911^NS
HNP (mm) (PNS to Ba-N plane)	21.76 ± 1.78	21.93 ± 2.22	0.471^NS	21.25 ± 1.85	21.78 ± 2.20	0.034*	0.258^NS
DOP (mm) (U-MPW)	9.19 ± 2.03	10.73 ± 2.45	0.000***	7.81 ± 2.13	8.70 ± 1.80	0.010*	0.013*
DHP (mm) (V-LPW)	12.53 ± 2.80	14.30 ± 2.99	0.005**	12.84 ± 2.12	13.21 ± 2.15	0.516^NS	0.081^NS
SPL (mm) (U-PNS)	30.56 ± 3.41	30.01 ± 3.25	0.136^NS	30.78 ± 2.85	30.88 ± 3.25	0.740^NS	0.365^NS
SPT (mm) (Maximum thickness of the soft palate)	7.24 ± 1.15	7.48 ± 1.02	0.135^NS	7.11 ± 0.76	7.09 ± 0.96	0.845^NS	0.287^NS
SPI (°) (Ptm per × PNS-U)	46.75 ± 4.72	44.22 ± 3.90	0.019*	42.35 ± 5.40	44.30 ± 4.82	0.068^NS	0.045*

SD indicates standard deviation; NS, nonsignificant; *P < .05; **P < .01; ***P < 0.001.
DNP, depth of the nasopharynx; HNP, height of the nasopharynx; DOP, depth of the oropharynx; DHP, depth of the hypopharynx; SPL, soft palate length; SPT, soft palate thickness; and SPI, soft palate inclination.